Patent 6091612: Universal power supply for arc welder
(ELECTRIC POWER CONVERSION SYSTEMS : CURRENT CONVERSION : With means to introduce or eliminate frequency components : In rectifier systems : Including means for reducing ripples from the output : Including notching)

Patent 6091615: Resonant power converter
(ELECTRIC POWER CONVERSION SYSTEMS : CURRENT CONVERSION : With condition responsive means to control the output voltage or current : Cooperating separate sensing and control means : For inverter : With transistor control means in the line circuit : For bridge-type inverter : With plural control windings)